textproduct: Albany

WHAT HAS CHANGED

Winter Weather Advisory remains over eastern NY and western New England late this pm thru tonight. A sharper transition from mixed pcpn to snow may occur with a secondary low near southeast New England Wed morning for the northern Taconics, southern VT and the Berkshires Wednesday morning with light accumulations.

KEY MESSAGES

1. A light wintry mix will impact eastern NY and western New England late this afternoon through Wednesday morning. Although total ice and snow amounts are fairly light, slippery travel is expected, especially for northern and high terrain areas, where the colder air will linger the longest.

2. Snowmelt due to warming temps and rain will allow for increased runoff for late Thursday through the weekend. River rises are expected, although the confidence for any ice jam or river flooding is still low at this time.

DISCUSSION

KEY MESSAGE 1...

A low pressure system will quickly approach from the Great Lakes Region this afternoon into tonight. Clouds will continue to thicken and lower, as the isentropic lift will increase ahead of the fast wave and its warm front for mixed pcpn to break out between 4-7 pm west of the Hudson River Valley/Lake George. The pcpn may initially start as rain/snow and then transition to freezing rain and snow/sleet due to wet bulb cooling and warmer air moving in a loft with some colder subfreezing air trapped at the sfc. The sub freezing column is cold and deep enough for a period of snow over the northern zones including the southwest Dacks, Lake George Saratoga Region and southern VT. Some sleet may mix with the snow prior to midnight. Further south of those areas, periods of freezing rain and rain will develop with temps hovering in the upper 20s to lower 30s. For the Capital District, mid Hudson Valley, southern Taconics and southern Litchfield Co. in NW CT we phrased the forecast as rain/rain likely with a chance of freezing rain and the advisory runs still to 4 am, as temps do rise overnight. The higher terrain areas of the eastern Catskills, northern Taconics and Berkshires may accrete ice better based on the model soundings, critical thickness profiles and the FRAM output in the CAMs, such as the HREFs. We are not expecting a significant ice event, but a nuisance or low grade event that could cause some slick spots on roads and untreated surfaces. The valley areas will generally see under one tenth of an inch of flat ice. The higher terrain and the Mohawk Valley may receive one to two tenths of flat ice including southern VT. An inch or less of snow is possible from the Greater Capital Region south.

The Winter Weather Advisories continue to be in effect for the entire region due to the ice and modest snow accums across the northern zones. The ice amounts should be light enough to limit any power outages. Some of the high resolution CAMs show a secondary low forming near southeast New England Wed morning, and then lifting northeast of Cape Cod during the afternoon. Colder air will be drawn back into the system for a transition from rain/mixed pcpn back to snow and sleet with a light accums of an inch or two over the northern Taconics, southern Greens and Berkshires. The pcpn should end by the early to mid pm. Lows fall back into the mid/upper 20s to lower 30s and rise overnight. Highs on Wed rise slightly above normal with lower to mid 30s over the higher terrain and mid 30s to lower 40s in the valleys with breezy west/northwest winds in the afternoon of 10-20 mph.

KEY MESSAGE 2...

High pressure builds in Wed night into Thu with mainly fair and dry weather with temps modifying to normal to above normal readings, as ridging builds in over the East Coast. As mid and upper level heights increase over the East Coast, a storm system will eject out of the southern Plains into the Midwest and the Lower Great Lakes Region. Above normal temps at the sfc and aloft move into the region. A warm front may bring a light mix of spotty freezing rain or plain rain to the region Thu night/Fri morning with lows in the mid 20s to lower 30s climbing overnight. Some diurnal snow melt may occur Thu, but should slow Thu night before the surge of milder air moves in ahead of the wave moving into the central and eastern Great Lakes.

The initial wave passes north and west of the region on Friday with a good chance of showers. The QPF does not look too excessive based on the NBM and WPC with a tenth to third of inch with the wave and front. A better chance of rainfall looks to be on the first half of the weekend with a trailing wave along the boundary that moves into the Ohio Valley/eastern Great Lakes Region on Saturday. The warm front will focus another round of rain with perhaps some mixed pcpn over the northern most zones. An additional quarter to half inch of rainfall may occur with small stream/creek flows increasing and some snow melt. This may cause some ice break up in the southern basins and an isolated ice jam problem or minor hydro issue. Much of the rainfall should be absorbed in the deeper snow pack.

Again...some isolated/localized issues can not be ruled out and we will monitor this situation this weekend. Temps will run 10-15 degrees above normal in the upper 30s/40s to close to 50F Fri and Sat and will fall back to seasonable levels with the cold frontal passage for Sunday into Monday with scattered snow showers and flurries.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

Mainly VFR conditions through 21 UTC today before ceilings gradually lower to MVFR ahead of our next wintry mix precipitation event. Expecting temperatures to hover in the low 30s (upper 20s at GFL) tonight at all terminals which will support a period of freezing rain arriving from southwest to northeast at POU/ALB/PSF and as snow at GFL between 22 and 02 UTC. Once wintry mix arrives, expecting cigs and vis to drop to IFR. Temperatures likely remain locked in the low 30s much of the night maintaining freezing rain at POU/ALB/PSF while snow at GFL mixes with freezing rain and sleet from 06-10 UTC. Precipitation turns lighter for a period from 09 - 12 UTC allowing vis to trend upwards to MVFR briefly before a second period of steady precipitation arrives from west to east around 12-13 UTC. This will likely lead to a transition to steady snow or snow/sleet at GFL/PSF/ALB with vis trending down to IFR vis through at least 15 UTC. Expecting mainly rain at POU as temperatures remain a bit milder. Once the steady precipitation exits to our east by 15 - 18 UTC, vis should improve back to MVFR but cigs will slowly improve from IFR to low end MVFR at ALB and POU while GFL/PSF likely remain IFR through the end of the TAF cycle.

Winds will be light and variable through late this afternoon, increasing to 4-8 kt from the E/SE at ALB/POU/PSF this evening and early tonight, before becoming light and variable again after midnight.

Outlook...

Wednesday Night: No Operational Impact. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. Thursday Night: No Operational Impact. NO SIG WX. Friday: High Operational Impact. Definite RA. Friday Night: Moderate Operational Impact. Chance of RA. Saturday: High Operational Impact. Likely RA. Saturday Night: High Operational Impact. Likely RA. Sunday: Moderate Operational Impact. Breezy. Chance of SHRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...Winter Weather Advisory until 11 AM EST Wednesday for CTZ001. Winter Weather Advisory until 4 AM EST Wednesday for CTZ013. NY...Winter Weather Advisory until 11 AM EST Wednesday for NYZ032- 033-038>043-047-048-050-051-058-063-082>084. Winter Weather Advisory until 4 AM EST Wednesday for NYZ049- 052>054-059>061-064>066. MA...Winter Weather Advisory until 11 AM EST Wednesday for MAZ001- 025. VT...Winter Weather Advisory until 11 AM EST Wednesday for VTZ013>015.